feat: add AttributedOnPolicyEvaluator

[arjavdongaonkar]

add AttributedOnPolicyEvaluator for vulnerability age-based policy evaluation

Implements production-ready evaluator with caching, error handling, and comprehensive logging. Supports ISO-8601 period formats with injectable dependencies for testing.

Description

Addressed Issue

Additional Details

Checklist

• [x] I have read and understand the contributing guidelines
• [ ] This PR fixes a defect, and I have provided tests to verify that the fix is effective
• [x] This PR implements an enhancement, and I have provided tests to verify that it works as intended
• [ ] This PR introduces changes to the database model, and I have added corresponding update logic
• [x] This PR introduces new or alters existing behavior, and I have updated the documentation accordingly

[owasp-dt-bot]

:tada: Snyk checks have passed. No issues have been found so far.

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